Hydraulic atomizing spray gun



April 28, 1964 D. o. SILL 3,130,910

HYDRAULIC ATOMIZING SPRAY GUN Filed May 21, 1962 2 Sheets-Sheet l INV EN TOR.

ATTORNEYS.

A ril 28, 1964 D. o. SILL 3,130,910

HYDRAULIC ATOMIZING SPRAY GUN Filed May 21, 1962 2 Sheets-Sheet 2 IN VEN TOR.

93 9 oq mzazwa 945% WWW ATTHRNEYS United States Pa n F 3,130,910 HYDRAULIC ATOMIZING SPRAY GUN Donald 0. Sill, West Des Moines, Iowa, assignor to Delavan Manufacturing Company, Des Moines, Iowa, a corporation of Iowa Fiied May 21, 1962, Ser. No. 196,182

2 Claims. (Cl. 239404) This invention relates to a hydraulic atomizing spray gun suitable for use with a variety of materials such as urethane foam formulations, multi-component resins such as epoxies and polyesters Wherien the material and a suitable catalyst or curing agent are hydraulically mixed within the nozzle itself without the use of atomizing air or other agent before the resulting mixture is discharge from the nozzle, the nozzle also being capable of use for spraying reinforced plastics by introducing chopped glass fibers or the like to the stream of resin or the like introduced to the nozzle.

One object of the invention is to provide a relatively simple spray gun head having a nozzle mounted therein, and two lines of liquid leading to the nozzle, each controlled by a valve, the nozzle having means for receiving the separate fluids and efliciently intermixing them before discharging them, and the gun having a trigger for open-' 3,130,910 Patented Apr. 28, 1964 between operations when changing from one material to ing the valves as desired for controlling the How of fluids to the nozzle.

Another object is to provide "a'nozzle in which two streams of cone-shaped rotateeither in opposite directions or in the same direction, and wherein the streams tend to cross laterally in relation to each other to thereby produce an eflicient intermixing action of the fluids, the aranother.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my hydraulic atomizing spray gun,

wherby the objects above contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in detail on the accompanying drawings, wherein:

FIG. 1 is a front elevation of a hydraulic atomizing spray gun embodying my invention.

FIG. 2 is a side elevation thereof on a reduced scale.

FIG. 3 is an enlarged horizontal sectional view on the line 3-3 of FIG. 2 showing the parts on an enlarged scale and in reverse order relative to- FIG. 2.

FIG. 4 is an enlarged sectional view of the three parts of the nozzle per se shown at the left end of FIG. 3 removed from the head of the gun.

FIG. 5 is a separated View of the parts of FIG. 4, one in section and the other two in side elevation.

FIGS. 6 and 7 are end elevations according to the lines 6-6 and 77 of FIG. 5, and

FIG. 8 is a perspective view ot the parts of FIGS. 6 and .7 but with swirl slots arranged for the same direction of rotation instead of opposite directions of rotations as in FIGS. 5, 6, and 7.

. g 10 has a pair of wings 14 perforated as at 16 (seeFIG. 3)

and a pair of bosses 18 having sockets 20. 4 I

Ahead H is provided having a threaded socket 22 receiving a screw 24 which serves to hold the head H assembled relative to the gun body 10. The head H has a "pair of valve seats 26 and 28 against which valves 30 and rotating motion tends to spread the fluids into thin films in I which the primary film is allowed to expand in a conical form as it exists, and the secondary film is confined to a cylindrical form whereby the two fluids are mixed as a result of impinging of the primary fluid upon the secondary, and the turbulence caused by the rotation.

' Still another object is to provide the head of the gun designed for removable reception of the nozzle so that the nozzle can be removed for cleaning or replacement by a different type of nozzle.

A further object is to provide the trigger of the gun so connected with the two valves thereof that either may be 32 are normally seated. Each of the valves 30 and 32 is provided with a valve stem 34, a packing retainer 36 there- 7 for, and an O-ring 38 for sealing purposes. For hydraulically balancing the valves 30 and 32, bores 40 are provided in the head H and a plug 42 on each stem 34 is opened slightly in advance of the other for introducing either liquid component flowing to the gun ahead of the other, particularly in allowing a curing agent or catalyst to be injected ahead of a resin if there is any danger that a trace of the resin might be sprayed without being mixed with the curing agent.

.Still a further object is to provide fluid control valves of hydraulically balanced type so as to minimize the size of closing springs therefor, and thus the opening pressure required on the trigger of the gun, the gun being thereby very sensitive as to the size of the spray issuing from the nozzle thereof and easy to control.

An additional object is to provide a latch on the trigger whereby the valves of the gun may be locked in open slidable in the bores 40 and sealed by of means O-rings 44,

as the valve seats 26 and 28.

For normally seating the valves 30 and 32 on the seats 26 and 28 springs 46 are provided on the stems 34 interposed between the bosses 18 and collars 48 mounted by means of said screws on the stems 34. To unseat the valves a trigger 50 is pivoted at 52 to the gun body 10 and has a pair of wings 54 to engage the collars 48 and move them toward the right in FIG. 3 when the trigger 50 is moved toward the left in FIG. 2. The collars 48 may be individually adjusted so that one of the valves 30 and 32 may be made to open slightly in advance of the other for a purpose which will hereinafter appear.

The trigger 50 is provided. with a latch 56 pivoted thereto and biased to the full line of position shown in FIG. 2. The left hand end of the latch 56 is adapted to coact with an abutment 58 during sustained spraying operations by using the forefinger of the hand grasp ing the handle 12 and the trigger 50 to raise the right hand end of the trigger so that it assumes the dotted position. The left hand end of the trigger may then be latched behind the abutment 58. When it is desired to reclose the valves, it is merely necessary to depress the trigger 50 and then unlatch the latch 56 from the abutment 58 whereupon the springs 46 will reclose the valves. The mounting of the head H by means of the screw 24 on the body 10, and the reception of the outer ends cavities 64 and 66 (see FIG. 3) may face downwardly and the hose connections thereto accordingly depend from the spray gun. By loosening the screw 24 and rotating the head H 180 as indicated by arrows a in FIG. 1 the inlets 60 and 62 extend upwardly to connect to supply hoses that come down from overhead.

The outlet sides of the valves 30 and 32 communicate with outlet passageways 68 and 70 respectively as shown in FIG. 3. A plug 72 closes the outer end of the passageway 68 whereas the outer end of the passageway 70 has a solvent valve shown generally at 74 mounted therein. This valve is adapted to be connected by a third flexible hose to a supply of solvent, for use whenever desired merely by opening the valve 74, the solvent being under pressure so that it is forced through the open valve 74 and the passageway 70 and then through the parts of a nozzle N for cleaning purposes.

The nozzle N comprises a nozzle body shown generally at 76, an outer distributor shown generally at 78 and an inner distributor shown generally at 80. The nozzle body 76 has a cylindrical bore 82, a conical bore 84, a second cylindrical bore 86 and a conical bore 88 as shown in FIG. 5. The cones 84 and 88 incline in opposite directions.

The outer distributor 78 has a flange 90 adapted to be received in the cylindrical bore 82 and a square flange 92 also adapted to be received therein so that fluid may flow past the flange 92 except at the corners thereof. The flange 90 is provided with a series of angular slots 94 adapted to swirl the fluid.

The inner distributor 80 has a pair of flanges 96 and 98, the flange 96 being provided with swirl slots 99 which as shown in FIG. may be inclined in the opposite direction in relation to the slots 94, or as shown in FIG. 8 both the slots 94 and 99 may cause swirling in the same direction. The inner distributor 80 has a bore 97 leading thereinto as shown in FIG. 4 and a cross bore 95 leading therefrom to the space within the outer distributor 78 defined by a cylindrical bore 93. The outer distributor 78 also has a pair of conical bores 91 and 89 similar to the conical bores 84 and 88 respectively of the nozzle body 76, and a cylindrical transition bore 87 between the conical bores 91 and 89. The conical bores 84 and 91 may be considered as reducing bores and the conical bores 88 and 89 as expanding bores when considered as to their action on fluids flowing through them.

As shown in FIG. 3 the nozzle N is mounted by screwing it into a threaded bore 81 of the head H, and the parts thereof are sealed relative to the head by O-rings 83 and 85. As shown in FIG. 1 the nozzle body 76 is provided with a pair of flats 79 whereby a wrench may be used for screwing the nozzle into or out of the head. The nozzle parts are thereby readily removable for interchangeability of the inner distributor 80 for either reverse or same-direction fluid flow according to FIGS. 5 and 8, or for mounting any other suitable nozzle in the head H such as one for producing a flat spray instead of a hollow cone-shaped spray.

As for the action of the fluid within the nozzle N, reference is made to FIG. 4 in which fluid F1 flows from the inlet cavity 64 of FIG. 3 past the valve 30 and through the outlet passageway 68; then through the bores 97 and 95 of the inner distributor 80 of FIG. 4 and through the slots 99 thereof as indicated by arrows. The slots produce a swirling action on the flowing fluid and centrifugal force thereupon tends to confine the fluid to a film as illustrated along the bores 91, 87 and 89, so that the fluid issues in an expanding cone-shaped film from the cone-shaped bore 89. At the same time the fluid F2 from the inlet passageway 66 past the valve 32 and through the outlet passageway 70 enters the nozzle body 76 and flows past the outer distributor 78, the slots 94 thereof producing a swirling action that causes the fluid F2 to be confined to a film along the bores 84 and 86 of 4 the nozzle body 76, and likewise of the mixed fluids F3 along the bore 88.

The expanding film of fluid F1 from the cone-shaped bore 89 laterally impinges the fluid F2 as shown at 77 and whether the films are rotating in the same or opposite directions produces a turbulence that thoroughly mixes one fluid with the other without the necessity of using atomizing air or the like for this purpose. In other words the mixing of the two fluids is purely hydraulic and there is no air used which might produce undesirable overspray. Atomization and mixing are achieved hydraulically through impingement of the primary and secondary sprays, one laterally relative to the other at the tip of the spray gun.

As the hollow cone of mixed liquid L3 issues from the nozzle N it progresses from a solid film to ligaments and then to droplets which are deposited on the mold surface or any other surface desired to be coated by the mixture of plastic and curing agent.

My spray gun thus atornizes by purely hydraulic action adjacent the spnay tip as distinguished from mix-ing externally outside the gun or in a mixer previous to supplying the rnixture to the gun. This is very critical, especially with urethane foams. Most spray guns which have internal mixing chambers are readily susceptible to contamination and require frequent and thorough cleaning whereas in my gun, since the two fluids are mixed substantially at the point of discharge, this trouble is eliminated.

By using the solvent valve 74 the gun is readily adaptable to solvent flushing. Solvents such as acetone or methylene chloride are frequently injected through the metering parts to prevent contamination and plugging during intermittent operation or during periods of shutdown. The solvent is introduced through external fittings into the secondary metering system. My gun is also adapted as a pour nozzle required when introducing foam resin into molds or cavities not involving a surface to be sprayed. The latch 56 for this purpose may be adjusted to hold the valves farther open than normal by adjusting the abutment 58 which is screw-threadedly mounted in the gun body 10.

Some changes may be made in the construction and arrangement of the parts of my spray gun without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents which may reasonably be included within their scope.

I claim as my invention:

1. In a hydraulic atomizing spray gun, a gun body having a 'head, a pair of valves in said head, a trigger pivoted to said body and operatively connected with both of said valves for opening them, a nozzle mounted in said head and receiving fluids from both of said valves, said nozzle having an expanding cone for one fluid and a contracting cone for the other fluid, said expanding cone being located within said contracting cone, means for producing rotation of both fluids whereby each forms a film on the surface of its cone, said expanding cone delivering its film of fluid substantially laterally with respect to the film of fluid delivered by said contracting cone whereby lateral impingement of the first film with respect to the second film and rotation of the fluids thoroughly intermixes them, said nozzle having an expanding cone-shaped discharge opening for directing the two mixed fluids in a film therealong and into a hollow cone shape due to the rotation thereof as the fluids are sprayed from said nozzle, said head having inlet openings directed downwardly therefrom for connection with upwardly extending fluid supply hoses, said head being rotatable relative to said gun body whereby the hoses may extend to said head from an overhead position, a screw at the axis of rotation threaded [into one of said .gun body and said head and clamping the other thereto, and means of coaction between said gun body and said head located apart to prevent relative rotation of one relative to the other about said screw.

2. In a hydraulic atomizing spnay gun, a gun body having a head, a pair of valves in said head, a trigger pivoted to said body and operatively connected with both of said valves for opening them, a nozzle mounted in said head and receiving fluids from both of said valves, said nozzle having an expanding cone for one fluid and a contracting cone for the other fluid, said expanding cone being located Within said contracting cone, means for producing rotation of both fluids whereby each forms a film on the surtfiace of its cone, said expanding conei delivering its film of fluid substantially laterally with respect to the film of fluid delivered by said contracting cone whereby lateral impingement of the first film with res ct to the second film and rotation of the fluids thoroughly intermixes them, said nozzle having an expanding cone-shaped discharge opening for directing the two mixed fluids in a film therealong and into a hollow cone shape due to the rotation thereof as the fluids are sprayed from said nozzle, each of said valves comprising a valve member, a plunger spaced therefrom, a valve stem connecting said valve member and said plunger together, said head having a seat 01 said valve member to engage in the valve-closed position and a bore aligned therewith in which said plunger is slidable, said stem extending from said head to the exterior thereof for openation by said trigger, and the area of said valve seat being substantially the same as the area of said bore to provide a hydraulically balanced type of valve.

References Cited in the file of this patent UNITED STATES PATENTS 1,315,765 Ecloart Sept. 9, 1919 1,382,640 Heinrich June 28, 1921 2,703,260 Olson et a1. Mar. 1, 1955 2,813,751 Barrett Nov. 19, 1957 2,831,754 Manka Apr. 22, 1958 2,953,248 Troland Sept. 20, 1960 2,971,700 Peeps Feb. 14, 1961 3,013,732 Webster Dec. 19, 1961 3,074,651 Agosti et a1. I an. 22, 1963 

1. IN A HYDRAULIC ATOMIZING SPRAY GUN, A GUN BODY HAVING A HEAD, A PAIR OF VALVES IN SAID HEAD, A TRIGGER PIVOTED TO SAID BODY AND OPERATIVELY CONNECTED WITH BOTH OF SAID VALVES FOR OPENING THEM, A NOZZLE MOUNTED IN SAID HEAD AND RECEIVING FLUIDS FROM BOTH OF SAID VALVES, SAID NOZZLE HAVING AN EXPANDING CONE FOR ONE FLUID AND A CONTRACTING CONE FOR THE OTHER FLUID, SAID EXPANDING CONE BEING LOCATED WITHIN SAID CONTRACTING CONE, MEANS FOR PRODUCING ROTATION OF BOTH FLUIDS WHEREBY EACH FORMS A FILM ON THE SURFACE OF ITS CONE, SAID EXPANDING CONE DELIVERING ITS FILM OF FLUID SUBSTANTIALLY LATERALLY WITH RESPECT TO THE FILM OF FLUID DELIVERED BY SAID CONTRACTING CONE WHEREBY LATERAL IMPINGEMENT OF THE FIRST FILM WITH RESPECT TO THE SECOND FILM AND ROTATION OF THE FLUIDS THOROUGHLY INTERMIXES THEM, SAID NOZZLE HAVING AN EXPANDING CONE-SHAPED DISCHARGE OPENING FOR DIRECTING THE TWO MIXED FLUIDS IN A FILM THEREALONG AND INTO A HOLLOW CONE SHAPE DUE TO THE ROTATION THEREOF AS THE FLUIDS ARE SPRAYED FROM SAID NOZZLE, SAID HEAD HAVING INLET OPENINGS DIRECTED DOWNWARDLY THEREFROM FOR CONNECTION WITH UPWARDLY EXTENDING FLUID SUPPLY HOSES, SAID HEAD BEING ROTATABLE RELATIVE TO SAID GUN BODY WHEREBY THE HOSES MAY EXTEND TO SAID HEAD FROM AN OVERHEAD POSITION, A SCREW AT THE AXIS OF ROTATION THREADED INTO ONE OF SAID GUN BODY AND SAID HEAD AND CLAMPING THE OTHER THERETO, AND MEANS OF COACTION BETWEEN SAID GUN BODY AND SAID HEAD LOCATED 180* APART TO PREVENT RELATIVE ROTATION OF ONE RELATIVE TO THE OTHER ABOUT SAID SCREW. 